<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>
   <el-form label-width="120px">
        <el-form-item label="课程标题">
            <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
        </el-form-item>
        <!-- 所属分类 TODO -->
        <el-form-item label="课程分类">
            <el-select
                v-model="courseInfo.subjectParentId"
                placeholder="一级分类" @change="subjectLevelOneChanged">
                    <el-option
                        v-for="subject in subjectOneList"
                        :key="subject.id"
                        :label="subject.title"
                        :value="subject.id"/>
            </el-select>

        <!-- 二级分类 -->
            <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
                <el-option
                    v-for="subject in subjectTwoList"
                    :key="subject.value"
                    :label="subject.title"
                    :value="subject.id"/>
            </el-select>
        </el-form-item>


        <!-- 课程讲师 -->
        <el-form-item label="课程讲师">
        <el-select
            v-model="courseInfo.teacherId"
            placeholder="请选择">
            <el-option
                v-for="teacher in teacherList"
                :key="teacher.id"
                :label="teacher.name"
                :value="teacher.id"/>
        </el-select>
        </el-form-item>

        <el-form-item label="总课时">
            <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
        </el-form-item>
        <!-- 课程简介 TODO -->
        <el-form-item label="课程简介">
            <tinymce :height="300" v-model="courseInfo.description"/>
        </el-form-item>
        <!-- 课程封面-->
        <el-form-item label="课程封面">
            <el-upload
                :show-file-list="false"
                :on-success="handleAvatarSuccess"
                :before-upload="beforeAvatarUpload"
                :action="BASE_API+'/eduoss/fileoss'"
                class="avatar-uploader">
                <img :src="courseInfo.cover">
            </el-upload>
        </el-form-item>

        <el-form-item label="课程价格">
            <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
        </el-form-item>
        <el-form-item>
            <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
        </el-form-item>
    </el-form>
  </div>
</template>

<script>
import course from '@/api/edu/course'
import subject from '@/api/edu/subject'
import Tinymce from '@/components/Tinymce'
export default {
    components: {Tinymce},
    data() {
        return {
            saveBtnDisabled: false,
            courseInfo: {
                title: '',
                subjectId: '', //二级分类id
                subjectParentId: '',//一级分类id
                teacherId: '',
                lessonNum: '',
                description: '',
                cover: '/static/123.jpg',
                price: 0
            },
            teacherList: [],//封装所有的讲师数据
            subjectOneList: [],//一级分类
            subjectTwoList: [],//二级分类
            BASE_API: process.env.BASE_API//API接口地址
        }
    },
    created() {
        this.init();
    },
    watch: {
        $route(to,from) {
            this.init();
            this.courseInfo = {}
            this.courseInfo.cover = '/static/123.jpg';
            this.courseInfo.description = '';
            console.log("该方法已执行")
        }
    },
    methods: {
        init() {
            //获取路由的id值
            if(this.$route.params && this.$route.params.id) {
                this.courseId = this.$route.params.id;
                //调用根据id查询信息
                this.getInfo();
            } else {
                //初始化所有讲师
                this.getListTeacher();
                //初始化一级分类
                this.getOneSubject();
            }
        },
        //根据课程id查询信息
        getInfo() {
            course.getCourseInfoId(this.courseId)
                .then(response => {
                    this.courseInfo = response.data.courseInfoVo;
                    //1查询所有的分类，包含一级和二级
                    subject.getSubjectList()
                        .then(response => {
                           //2获取所有一级分类
                           this.subjectOneList = response.data.list;
                           //3把所有一级分类数组进行遍历，比较当前courseInfo里面一级分类id和所有的以及分类id
                           for(var i=0;i<this.subjectOneList.length;i++) {
                               //获取每个一级分类
                               var oneSubject = this.subjectOneList[i];
                               //比较当前courseInfo里面一级分类id和所有一级分类id
                               if(this.courseInfo.subjectParentId == oneSubject.id) {
                                   //获取一级分类所有二级分类
                                   this.subjectTwoList = oneSubject.children
                               }
                           }
                        })
                    //初始化所有讲师
                    this.getListTeacher();
                })
        },
        //上传封面成功调用的方法
        handleAvatarSuccess(res, file) {
           this.courseInfo.cover = res.data.url;
        },
        //上传之前调用的方法
        beforeAvatarUpload(file) {
            const isJPG =  file.type === 'image/jpeg'
            const isLt2M = file.size / 1024 / 1024 < 2

            if(!isJPG) {
                this.$message.error('上传头像图片只能是JPG格式！');
            }
            if(!isLt2M) {
                this.$message.error('上传头像图片大小不能超过2MB');
            }
            return isJPG && isLt2M;
        },
        //点击某一个一级分类，触发change，显示对应二级分类
        subjectLevelOneChanged(value) {
            //value就是一级分类id值
            //遍历所有的分类，包含一级和二级
            for(let i=0;i<this.subjectOneList.length;i++) {
                //每个一级分类
                var oneSubject = this.subjectOneList[i];
                //判断：所有一级分类id和点击一级分类id是否一样
                if(value === oneSubject.id) {
                    //从一级分类获取里面的所有二级分类
                    this.subjectTwoList = oneSubject.children;
                    //把二级分类id值清空
                    this.courseInfo.subjectId = '';
                }
            }
        },
        //查询所有的一级分类
        getOneSubject() {
            subject.getSubjectList()
                .then(response => {
                   this.subjectOneList = response.data.list;
                   console.log(this.subjectOneList)
                })
        },
        //查询所有的讲师
        getListTeacher() {
            course.getListTeacher()
                .then(response => {
                   this.teacherList = response.data.items;
                })
        },
        //添加课程
        addCourse() {
            course.addCourseInfo(this.courseInfo)
                    .then(response => {
                        //提示
                        this.$message({
                            type: "success",
                            message: "添加课程信息成功"
                        });
                //跳转到第二步
                    this.$router.push({path: '/course/chapter/' + response.data.courseId});
                })
        },
        //修改课程
        updateCourse() {
            course.updateCourseInfo(this.courseInfo)
                .then(response => {
                    //提示
                    this.$message({
                            type: "success",
                            message: "修改课程信息成功"
                        });
                    this.$router.push({path: '/course/chapter/'+ this.courseId});
                });
        },
        saveOrUpdate() {
            //判断添加或者修改
            if(!this.courseInfo.id) {
                //添加
                this.addCourse();
            } else {
                //修改
                this.updateCourse();
            }
        }
    }
}
</script>
<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>